CCAAT/增强子结合蛋白同源蛋白与钙联蛋白在内侧颞叶癫痫模型小鼠海马中的表达

Expressions of CCAAT / enhancer-binding Protein Homologous Protein and Calnexin in the Hippocampus of a Mouse Model of Mesial Temporal Lobe Epilepsy

目的观察CCAAT/增强子结合蛋白同源蛋白(CHOP)及钙联蛋白(CNX)在内侧颞叶癫痫小鼠海马区域中表达的时间和空间分布。方法采用海人酸(KA)诱导内侧颞叶癫痫小鼠模型,免疫印迹和免疫荧光技术检测CHOP和CNX在急性期(12、24 h)小鼠海马CA3区的表达量及分布差异,并与注射PBS的正常小鼠进行对照。结果免疫印迹检测结果显示,KA注射后12 h小鼠海马中的CHOP(F=1.136,P=0.4069)和CNX表达量(F=2.378,P=0.2087)与对照组差异没有统计学意义,KA注射后24 h注射侧海马中的CHOP(F=8.510,P=0.0362)和CNX表达量(F=6.968,P=0.0497)明显高于对照组。免疫荧光结果显示,KA注射后12 h CHOP的表达主要集中于CA3区,注射后24 h在CA1和CA3区表达水平均升高;KA注射后24 h CHOP蛋白(F=24.480,P=0.0057)和CNX蛋白(F=7.149,P=0.0478)的表达量显著高于对照组。结论伴随着癫痫发作的产生,CHOP蛋白表达量上升,提示神经元内质网应激水平不断增加,可能需要更多CNX作为分子伴侣帮助更多未折叠蛋白完成折叠过程。

Objective To explore the temporal and spatial distribution of CCAAT/enhancer-binding protein homologous protein （CHOP） and calnexin （CNX） in the dentate gyrus of mesial temporal lobe epilepsy （mTLE） mouse model. Methods We used kainic acid （KA） to induce acute phase （12 h and 24 h） mTLE mouse models and performed Western blotting and immunofluorescence to detect the different expressions and dis- tribution pattern of CHOP and CNX in CA3 of the hippocampus. Results Compared with the controls, the ex-pressions of CHOP （ F = 1. 136, P = 0. 4069） and CNX （F = 2. 378, P = 0. 2087） did not increase in CA3 of hippoeampus 12 h following KA injection in the acute phase of mTLE mouse models, whereas the expressions in CAI and CA3 of hippocampus 24 h after injection were significantly higher （ F = 8. 510, P = 0. 0362 ; F = 6. 968, P = 0. 0497, respectively） . As shown by immunofluorescence analysis, CHOP was expressed mainly in CA3 of hippocampus 12 h after KA injection, and increased in CA1 and CA3 24 h after KA administration. Compared with the controls, the expressions of CHOP （ F = 24. 480, P = 0. 0057） and CNX （ F = 7. 149, P = 0. 0478 ） were significantly higher 24 h after KA injection. Conclusions The expression of CHOP increases along with the progression of seizures, indicating the increased level of endoplasmic reticulum stress. An increasing number of CNX, which serves as molecular chaperone, may be needed to facilitate the unfolded protein to com- plete the folding process.